A high-toughness and high-weather-resistance low-density polyethylene material, a preparation method and application thereof

Abstract

This invention provides a high-toughness, high-weather-resistance low-density polyethylene (LDPE) material and its preparation method. The LDPE material comprises the following components in parts by weight: 60-80 parts LDPE, 10-12 parts acrylate composite, 4-6 parts modified titanium dioxide, 15-20 parts modified zeolite powder, and 1-5 parts additives. The modified zeolite powder is a product of zeolite powder modified by silane impregnation; the modified titanium dioxide is a product of hydroxylated titanium dioxide coupled with polybutadiene rubber. This invention uses LDPE as the main component, compounded with modified zeolite powder and modified titanium dioxide, effectively improving the dispersion and bonding effects between different components, forming a more uniform and stable system. The synergistic effect of multiple components enhances the material's toughness and weather resistance, and it exhibits good processing performance, showing promising application prospects in products such as hoses.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-toughness, high-weather-resistant low-density polyethylene material, its preparation method, and its applications. Background Technology

[0002] Low-density polyethylene (LDPE) is widely used in flexible packaging in the daily chemical, pharmaceutical, and food industries due to its excellent flexibility, heat-sealing properties, and processing flowability. Its performance directly determines the effectiveness and lifespan of the flexible packaging. In practical use, flexible packaging frequently withstands external forces such as compression and bending, and may be exposed to natural light for extended periods. It also needs to possess certain barrier properties to prevent oxidation and leakage of the contents. Therefore, comprehensive requirements are placed on the material's toughness, weather resistance (light resistance), barrier properties, and heat-sealing properties.

[0003] Currently, conventional LDPE materials have significant performance shortcomings when used in hose manufacturing: their inherent toughness is limited, and they are prone to cracking and damage under long-term extrusion or low-temperature environments; their weather resistance is poor, and they are prone to photo-oxidative aging under long-term exposure to ultraviolet radiation, resulting in yellowing and brittleness of the material, a significant decrease in mechanical properties, and a shortened service life of the hose; at the same time, after long-term use, LDPE's barrier properties are insufficient, and the permeability of oxygen, moisture, etc., is easy to increase, making it difficult to meet the long-term storage requirements of easily oxidized contents.

[0004] Existing technologies often modify LDPE by adding inorganic fillers or modifiers. Zeolite powder, due to its regular pore structure, can improve the material's barrier properties and has strong thermal stability. However, unmodified zeolite powder has poor compatibility with LDPE and is prone to agglomeration, which negatively impacts the material's toughness. Titanium dioxide is a commonly used weather-resistant modifier that can absorb and scatter ultraviolet light to delay material aging. However, ordinary titanium dioxide also suffers from poor dispersibility and cannot promote the material's toughness. Furthermore, as application requirements increase, the material's weather resistance is becoming increasingly insufficient, limiting its application in high-performance hose materials. Therefore, existing modified LDPE materials often suffer from performance imbalances and struggle to simultaneously meet the comprehensive performance requirements of hoses.

[0005] Therefore, how to develop a product that overcomes the above-mentioned defects is a problem facing this field. Summary of the Invention

[0006] To address the shortcomings and deficiencies of existing technologies, this invention provides a high-toughness, high-weather-resistance low-density polyethylene material. This invention uses LDPE as the main component, compounded with modified zeolite powder and modified titanium dioxide, effectively improving the dispersion and bonding effects between different components, forming a more uniform and stable system. Through the synergistic effect of multiple components, the material's toughness and weather resistance are enhanced, and it exhibits good processing performance, showing promising application prospects in products such as hoses.

[0007] One object of the present invention is to provide a high-toughness, high-weather-resistant low-density polyethylene material, wherein the high-toughness, high-weather-resistant low-density polyethylene material comprises the following components in parts by weight: 60-80 parts of low-density polyethylene 10-13 parts of acrylate complex 4-6 parts of modified titanium dioxide 15-20 parts modified zeolite powder 1-5 parts of auxiliary agent; The modified zeolite powder is a product of zeolite powder modified by silane soaking; The modified titanium dioxide is a product of hydroxylated titanium dioxide coupled with polybutadiene rubber. The acrylate complex includes polydimethylsiloxane PEG-8 polyacrylate and polyacrylate impact modifiers.

[0008] Furthermore, the low-density polyethylene has a melt index of ≤60 g / 10min at 190°C and 2.16 kg.

[0009] Furthermore, the polybutadiene rubber is carboxyl-terminated polybutadiene liquid rubber (CTPB).

[0010] Furthermore, the amount of the auxiliary agent is 1 to 2 parts by weight.

[0011] Furthermore, the additives are selected from one or more of the following: compatibilizers, toughening agents, plasticizers, antioxidants, light stabilizers, dispersants, initiators, and preservatives.

[0012] Furthermore, the compatibilizer is maleic anhydride-grafted polyethylene (PE-G-MAH).

[0013] Furthermore, the amount of the compatibilizer is 1 to 1.5 parts by weight.

[0014] This invention contains polyacrylate components. Polydimethylsiloxane PEG-8 polyacrylate has the effects of interface regulation, lubrication and plasticization, and improved weather resistance. The absence of long-chain polyacrylate impact modifiers allows it to form an island structure to absorb impact energy. However, polyacrylate materials have a certain degree of polarity, resulting in insufficient compatibility with polyolefin systems. This invention uses maleic anhydride-grafted polyethylene as a compatibilizer, which also has an auxiliary toughening effect. This not only improves the interfacial bonding between polyacrylate and polyethylene, thus enhancing the stability and weather resistance of the composite material, but also shows good affinity with modified zeolite powder and modified titanium dioxide. The long chains intertwine and can also adsorb and bind through hydrogen bonding to form a synergistic toughening effect.

[0015] Furthermore, the silane is an alkylsilane coupling agent.

[0016] Furthermore, the alkylsilane coupling agent is at least one of isobutyltriethoxysilane or dodecyltriethoxysilane.

[0017] Furthermore, the alkylsilane coupling agent is dodecyltriethoxysilane.

[0018] Another object of the present invention is to provide a method for preparing the above-mentioned high-toughness, high-weather-resistant low-density polyethylene material, comprising the following steps: S1. Add zeolite powder to silane and react to obtain modified zeolite powder; S2. Hydroxylated titanium dioxide and polybutadiene rubber are mixed and reacted to obtain modified titanium dioxide; S3. Mix the modified zeolite powder, modified titanium dioxide and the remaining components, add them to an extruder, and extrude and granulate to obtain a high-toughness, high-weather-resistant low-density polyethylene material.

[0019] Furthermore, in step S1, the reaction temperature is 20-50℃ and the time is 36-50 h.

[0020] Furthermore, in step S2, the reaction temperature is 60-120℃ and the time is 4-12 h.

[0021] Further, in step S2, the mass ratio of the hydroxylated titanium dioxide to the polybutadiene rubber is 1:(0.1-1).

[0022] Another object of the present invention is to provide the application of the above-mentioned high-toughness, high-weather-resistant low-density polyethylene material in hoses.

[0023] The present invention has the following beneficial effects: This invention provides a high-toughness, high-weather-resistance low-density polyethylene material, whose main components include low-density polyethylene, acrylate composites, modified zeolite powder, and modified titanium dioxide. The modified zeolite powder is zeolite powder modified with an alkylsilane coupling agent, which coats the material surface with silane. The introduced alkylsilane is a non-polar inert structure, which improves the compatibility with the polyethylene matrix, thereby enhancing the dispersion effect, reducing the brittleness of the material, and avoiding the problem of easy water absorption and damage to the barrier and weather resistance of the composite material due to the strong hydrophilicity of zeolite itself. Modified titanium dioxide is a product of the reaction between hydroxylated titanium dioxide and carboxyl-terminated polybutadiene. On the one hand, it overcomes the problem of agglomeration and difficulty in dispersion caused by the strong polarity of hydroxylated titanium dioxide. On the other hand, the modified titanium dioxide dispersed in the system can form a multi-layered connection structure by entanglement between the long chains of polybutadiene, polyethylene, alkyl silane coupling agent modified zeolite powder, and long-chain polydimethylsiloxane PEG-8 polyacrylate. The modified zeolite powder particles play a skeleton role, while the modified titanium dioxide and polyacrylate impact modifier fill the gaps. The toughness of the composite material is enhanced by the synergistic effect of polybutadiene rubber, and the defect of product performance degradation caused by microcracks formed at the edges of large zeolite powder particles is avoided. Detailed Implementation

[0024] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0025] The terms "preferred," "more preferably," and "more suitable" used in this invention refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0026] It should be understood that, except in any operational instance or otherwise indicated, the amounts or all figures representing ingredients used, for example, in the specification and claims, should be understood to be modified by the term "about" in all cases. Therefore, unless otherwise stated, the numerical parameters set forth in the following specification and appended claims are approximate values ​​varying according to the desired performance to be obtained according to the invention.

[0027] The following raw materials are used in the embodiments and comparative examples of this invention: Low-density polyethylene: Sinopec PEM1850A.

[0028] Acrylic ester complex: polydimethylsiloxane PEG-8 polyacrylate (CAS No.: 217958-64-0) in a mass ratio of 3:1 and polyacrylate impact modifier (Kunshan Maijisen ACR-401).

[0029] Additives: antioxidant 1010 (mass ratio 0.5:1:0.5), compatibilizer maleic anhydride grafted polyethylene (ADMERNF410), and lubricant and dispersant polyethylene wax (AC-6A).

[0030] Carboxyl-terminated polybutadiene liquid rubber: carboxyl value 0.33-0.42 mmol / g, purchased from Zibo Qilong Chemical.

[0031] In the embodiments of this invention, "parts" refers to parts by mass.

[0032] Example 1 A high-toughness, high-weather-resistant low-density polyethylene material, wherein the high-toughness, high-weather-resistant low-density polyethylene material comprises the following components in parts by weight: 60 parts of low-density polyethylene 10 parts of acrylate complex 4 parts of modified titanium dioxide 15 parts modified zeolite powder Two portions of auxiliary agent; The preparation method of the above-mentioned high-toughness, high-weather-resistant low-density polyethylene material includes the following steps: S1. After washing and drying the zeolite powder (1000 mesh), soak it in isobutyltriethoxysilane (solid-liquid mass ratio of 1:10) at room temperature for 48 h. After filtration and drying, pulverize it to a particle size ≤3 mm to obtain modified zeolite powder. S2. Titanium dioxide (particle size 0.2-0.4 μm) was calcined at 500℃ for 2 h, cooled and then immersed in 2 mol / L NaOH solution (solid-liquid mass ratio 1:10), ultrasonically treated for 2 h, filtered, washed and dried to obtain hydroxylated titanium dioxide. Using 100 parts of toluene as a solvent, 10 parts of the hydroxylated titanium dioxide and 4 parts of carboxyl-terminated polybutadiene liquid rubber were mixed, heated to reflux for 6 h, cooled, filtered, washed and dried to obtain modified titanium dioxide. S3. According to the above-mentioned mass proportions, the modified zeolite powder, modified titanium dioxide and other components are mixed evenly, added to a twin-screw extruder, and extruded and granulated at 180-200℃ to obtain a high-toughness, high-weather-resistant low-density polyethylene material.

[0033] Example 2 A high-toughness, high-weather-resistant low-density polyethylene material, wherein the high-toughness, high-weather-resistant low-density polyethylene material comprises the following components in parts by weight: 60 parts of low-density polyethylene 10 parts of acrylate complex 4 parts of modified titanium dioxide 15 parts modified zeolite powder Two portions of auxiliary agent; The preparation method of the above-mentioned high-toughness, high-weather-resistant low-density polyethylene material includes the following steps: S1. After washing and drying the zeolite powder (1000 mesh), soak it in dodecyltriethoxysilane (solid-liquid mass ratio of 1:10) for 48 h at room temperature. After filtration and drying, pulverize it to a particle size ≤3 mm to obtain modified zeolite powder. S2. Titanium dioxide (particle size 0.2-0.4 μm) was calcined at 500℃ for 2 h, cooled and then immersed in 2 mol / L NaOH solution (solid-liquid mass ratio 1:10), ultrasonically treated for 2 h, filtered, washed and dried to obtain hydroxylated titanium dioxide. Using 100 parts of toluene as a solvent, 10 parts of the hydroxylated titanium dioxide and 4 parts of carboxyl-terminated polybutadiene liquid rubber were mixed, heated to reflux for 6 h, cooled, filtered, washed and dried to obtain modified titanium dioxide. S3. According to the above-mentioned mass proportions, the modified zeolite powder, modified titanium dioxide and other components are mixed evenly, added to a twin-screw extruder, and extruded and granulated at 180-200℃ to obtain a high-toughness, high-weather-resistant low-density polyethylene material.

[0034] Example 3 A high-toughness, high-weather-resistant low-density polyethylene material, wherein the high-toughness, high-weather-resistant low-density polyethylene material comprises the following components in parts by weight: 80 parts of low-density polyethylene 12.2 parts of acrylate complex 5.8 parts modified titanium dioxide 20 parts modified zeolite powder 3 parts of auxiliary agent; The preparation method of the above-mentioned high-toughness, high-weather-resistant low-density polyethylene material includes the following steps: S1. After washing and drying the zeolite powder (1000 mesh), soak it in dodecyltriethoxysilane (solid-liquid mass ratio of 1:10) for 48 h at room temperature. After filtration and drying, pulverize it to a particle size ≤3 mm to obtain modified zeolite powder. S2. Titanium dioxide (particle size 0.2-0.4 μm) was calcined at 500℃ for 2 h, cooled and then immersed in 2 mol / L NaOH solution (solid-liquid mass ratio 1:10), ultrasonically treated for 2 h, filtered, washed and dried to obtain hydroxylated titanium dioxide. Using 100 parts of toluene as a solvent, 10 parts of the hydroxylated titanium dioxide and 4 parts of carboxyl-terminated polybutadiene liquid rubber were mixed, heated to reflux for 6 h, cooled, filtered, washed and dried to obtain modified titanium dioxide. S3. According to the above-mentioned mass proportions, the modified zeolite powder, modified titanium dioxide and other components are mixed evenly, added to a twin-screw extruder, and extruded and granulated at 180-200℃ to obtain a high-toughness, high-weather-resistant low-density polyethylene material.

[0035] Comparative Example 1 A low-density polyethylene material, the difference between this comparative example and Example 1 is that in step S1, isobutyltriethoxysilane is replaced with γ-aminopropyltriethoxysilane; other components and preparation methods are the same as in Example 1.

[0036] Comparative Example 2 A low-density polyethylene material, the difference between this comparative example and Example 1 is that step S2 is modified as follows: S2. Titanium dioxide (particle size 0.2-0.4 μm) was calcined at 500℃ for 2 h, cooled and then immersed in 2 mol / L NaOH solution (solid-liquid mass ratio 1:10), ultrasonically treated for 2 h, filtered, washed and dried to obtain hydroxylated titanium dioxide. Ten parts of the hydroxylated titanium dioxide and four parts of carboxyl-terminated polybutadiene liquid rubber were mixed to obtain modified titanium dioxide. The other components and preparation methods are the same as in Example 1.

[0037] Comparative Example 3 A low-density polyethylene material, the difference between this comparative example and Example 1 is that all acrylate compounds are replaced with polyacrylate impact modifier (ACR-401).

[0038] Comparative Example 4 A low-density polyethylene material, the difference between this comparative example and Example 1 is that all acrylate compounds are replaced with polydimethylsiloxane PEG-8 polyacrylate.

[0039] Test case Performance tests were conducted on the high-toughness, high-weather-resistant low-density polyethylene materials prepared in the examples and comparative examples.

[0040] Test method: According to GB / T 1843—2008 and GB / T 1040.2 In 2022, the notched impact strength (Type A) and elongation at break were tested.

[0041] The sample was placed at a temperature of 70±1℃, a relative humidity of 85±5%, and an ultraviolet irradiation intensity of 260W / m².2 The environment was subjected to heat aging treatment for 10 days, and the notched impact strength after aging was measured.

[0042] The test results are shown in Table 1.

[0043] Table 1 Performance Test Results

[0044] Based on the above test results, it can be concluded that the polyethylene composite material of the present invention has high notched impact strength and elongation at break, and the impact strength retention rate after aging is above 85%, exhibiting good toughness and weather resistance. Furthermore, compared with Example 1, Examples 2-3 use long alkylsilane coupling agents to modify zeolite powder, and Examples 2-3 have even better performance.

[0045] Comparative Example 1 uses an aminosilane coupling agent to modify zeolite powder, introducing polar groups, but the improvement in compatibility is insufficient. The interfacial bonding effect between a large amount of zeolite powder and the polyethylene system is not ideal, and the toughness and weather resistance are significantly reduced compared to the examples. Comparative Example 2 directly mixes hydroxylated titanium dioxide and polybutadiene rubber, without forming a grafted or modified structure. The titanium dioxide is unevenly dispersed, easily agglomerates, and cannot entangle or bind with other components, making it difficult to exert a synergistic toughening effect, and the overall performance also declines. Comparative Example 3 replaces the acrylate compound with a polyacrylate impact modifier without long chains. The lack of entanglement effect reduces the interfacial bonding effect and synergistic effect, resulting in insufficient improvement in notched impact strength and elongation at break, and a decrease in weather resistance. Comparative Example 4 replaces the acrylate compound with polydimethylsiloxane PEG-8 polyacrylate, which reduces the absorption and buffering effect of external impacts, and consequently reduces impact strength and elongation at break, as well as weather resistance. Comparing Example 1, Comparative Example 3, and Comparative Example 4, it can be seen that polydimethylsiloxane PEG-8 polyacrylate and polyacrylate impact modifier can synergistically improve the toughness of polyethylene composite materials, and also show a certain synergistic effect on improving weather resistance.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-toughness, high-weather-resistant, low-density polyethylene material, characterized in that, The high-toughness, high-weather-resistant low-density polyethylene material comprises the following components in parts by weight: 60-80 parts of low-density polyethylene 10-13 parts of acrylate complex 4-6 parts of modified titanium dioxide 15-20 parts modified zeolite powder 1-5 parts of auxiliary agent; The modified zeolite powder is a product of zeolite powder modified by silane soaking; The modified titanium dioxide is a product of hydroxylated titanium dioxide coupled with polybutadiene rubber; The acrylate complex includes polydimethylsiloxane PEG-8 polyacrylate and polyacrylate impact modifiers.

2. The high-toughness, high-weather-resistant, low-density polyethylene material according to claim 1, characterized in that, The polybutadiene rubber is a carboxyl-terminated polybutadiene liquid rubber.

3. The high-toughness, high-weather-resistant, low-density polyethylene material according to claim 1, characterized in that, The additives are selected from one or more of the following: compatibilizers, toughening agents, plasticizers, antioxidants, light stabilizers, dispersants, initiators, and preservatives.

4. The high-toughness, high-weather-resistant low-density polyethylene material according to claim 3, characterized in that, The compatibilizer is maleic anhydride-grafted polyethylene.

5. The high-toughness, high-weather-resistant, low-density polyethylene material according to claim 1, characterized in that, The mass ratio of the polydimethylsiloxane PEG-8 polyacrylate to the polyacrylate impact modifier is (2~4):

1.

6. The high-toughness, high-weather-resistant low-density polyethylene material according to claim 5, characterized in that, The silane is an alkylsilane coupling agent; preferably, the alkylsilane coupling agent is at least one of isobutyltriethoxysilane or dodecyltriethoxysilane.

7. A method for preparing the high-toughness, high-weather-resistant low-density polyethylene material according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Add zeolite powder to silane and react to obtain modified zeolite powder; S2. Hydroxylated titanium dioxide and polybutadiene rubber are mixed and reacted to obtain modified titanium dioxide; S3. Mix the modified zeolite powder, modified titanium dioxide and the remaining components, add them to an extruder, and extrude and granulate to obtain a high-toughness, high-weather-resistant low-density polyethylene material.

8. The method for preparing the high-toughness, high-weather-resistant low-density polyethylene material according to claim 7, characterized in that, In step S1, the reaction temperature is 20-50℃ and the time is 36-50 h; in step S2, the reaction temperature is 60-120℃ and the time is 4-12 h.

9. The method for preparing the high-toughness, high-weather-resistant low-density polyethylene material according to claim 7, characterized in that, In step S2, the mass ratio of the hydroxylated titanium dioxide to the polybutadiene rubber is 1:(0.1-1).

10. The use of the high-toughness, high-weather-resistant low-density polyethylene material according to any one of claims 1-6 in hoses.

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